Like a carpentry shop littered with wood shavings after the work is done, debris left over from the formation of the Sun and planets is scattered throughout the inner solar system in the form of asteroids. Since the beginning, the Earth, the Moon and all of the planets have been hit by fragments of these objects from space. In addition to pieces of asteroids, Moon and Martian rocks have been found among the thousands of meteorites collected on Earth. In the past, meteorite falls were poorly understood phenomena and were frequently attributed to divine intervention. Many exaggerated stories developed and meteorites were often considered to be religious objects, some of which have been preserved in churches, temples, and burial chambers around the world.
Nowadays, there are expeditions whose goal is to collect meteorites in hot and cold deserts, including the Sahara and Antarctica, and space missions to planetary bodies aimed at providing new opportunities for scientific advancement. One of the most important findings regarding such bodies is that comets and certain types of meteorites contain organic molecules formed in space that may have had a relevant role in the origin of the first microorganisms on Earth. This review deals with the organic inventory of meteorites. Another review (to be published in the next issue of Int Microbiol) will focus on the organic content of comets.